This is a complete, ground-up rewrite of Minimal Firewall! The application has been migrated from .NET Framework 4.8 and WPF to the more modern .NET 8 and Windows Forms. This transition brings significant performance enhancements, a revamped user interface, and powerful new features.

Features

• Live Traffic Monitoring: A new "Live Connections" tab has been added to monitor active TCP connections and their associated processes in real-time, similar to tools like TCPView. More updates to come in this tab.

• Firewall Rule Groups: You can now manage firewall rule groups directly from a dedicated "Groups" tab, allowing you to enable or disable entire sets of rules at once.

• Enhanced Foreign Rule Detection: The previous manual scan for external rule changes has been replaced by a real-time Sentry Service. It uses WMI to watch for modifications the moment they happen and presents them in the "Audit" tab.

• Performance Caching: A new RuleCacheService has been implemented to significantly speed up application startup and data refreshes. It caches firewall rules both in-memory and to a local disk file to reduce reliance on slow API calls. When you close it to tray, it further reduces memory consumption.

Note: Temporarily Allow will be re-added in v2.1

🎨 UI

• Complete UI Rewrite: The user interface has been completely rebuilt using Windows Forms, replacing the previous WPF front-end.

• Custom Dark Mode Engine: A comprehensive dark mode system (DarkModeCS.cs) was modified from DarkModeForms to provide a consistent and modern look and feel in Windows Forms.

• Adaptive Advanced Rule Creator: The "Create Advanced Rule" form is now smarter. It adaptively shows or hides UI sections based on the selected network protocol (e.g., showing Port fields only for TCP/UDP).

Code & Backend Refactoring

• Framework Modernization: The entire project has been upgraded from the legacy .NET Framework 4.8 to .NET 8.

• Direct API Interaction: Advanced rules are now created by interacting directly with the NetFwTypeLib COM API, replacing the previous method of generating and executing PowerShell commands. This provides more robust and reliable rule creation.

• More Robust Services:

  • The

    AdminTaskService for running privileged operations like auditpol.exe now has improved error handling and output redirection .

  • The

    SystemDiscoveryService features an improved parser for extracting executable paths from Win32_Service WMI queries .

• Typed Data Models: New strongly-typed classes for PortRange and IPAddressRange have been introduced for more reliable parsing and handling of complex rule parameters.

To Download

The framework of the 1.7mb was set to Windows 8. It should work if you just want the smallest possible size (but remember, smaller doesn't mean a program uses less resources or is faster). The New framework is what I recommend using.

You may be prompted to download NET 8 from Microsoft if you are using an older system.